Absorbent pads including superabsorbent polymer particles interposed between two sheet materials of which at least one is water-permeable is widely known.
For example, the absorbent sheet disclosed in JP H5-38350 A (PTL 1) as an example of the absorbent articles is produced by following the steps of coating a sheet-like absorptive material with adhesive, dispersing superabsorbent polymer particles thereover, overlapping another sheet-like absorptive material therewith and finally integrating them under compression.
In the disposable wearing article disclosed in JP 3732320 B2 (PTL 2), a plurality of tubular portions extending in parallel to each other are formed of a water-permeable intermediate sheet underlying a liquid-permeable upper sheet and liquid-impermeable lower sheet wherein these tubular portions contain liquid-absorbent material including superabsorbent polymer particles in a range of 5 to 98% by mass.
In addition, the absorbent sheet disclosed in JP 2009-131510 A (PTL 3) is composed of an upper sheet, a lower sheet and superabsorbent polymer particles contained between these two sheets wherein the upper sheet and the lower sheet are partially joined to each other so as to surround respective non-bonded regions and to define respective pockets adapted to contain the superabsorbent polymer particles. Within the respective pockets, the superabsorbent polymer particles are movable.